Seismic reflector imaging by prestack time migration in the Kakkonda geothermal field, Japan

We show that a prestack migration method improves the S/N ratio of seismic reflection profiling in the Kakkonda geothermal field where seismic reflection data are of poor quality. We use non-iterative prestack time migration (PSTM), which does not require multiple iterations to determine the velocity structure for prestack time migration. The optimum constant migration velocity can be determined at each image point from a migration velocity analysis based on primary diffraction patterns. Our results delineate a strong reflector beneath a zone of high seismicity. According to the correspondence between the fracture distribution, the distribution of microearthquakes, and geothermal structure, this reflector is interpreted to be a zone of low-angle fractures saturated with hydrothermal fluids, and to be strongly controlled by the geothermal structure.     

Effect of ATRX and G‐Quadruplex Formation by the VNTR Sequence on α‐Globin Gene Expression

ATR‐X (α‐thalassemia/mental retardation X‐linked) syndrome is caused by mutations in chromatin remodeler ATRX. ATRX can bind the variable number of tandem repeats (VNTR) sequence in the promoter region of the α‐globin gene cluster. The VNTR sequence, which contains the potential G‐quadruplex‐forming sequence CGC(GGGGCGGGG)_n, is involved in the downregulation of α‐globin expression. We investigated G‐quadruplex and i‐motif formation in single‐stranded DNA and long double‐stranded DNA. The promoter region without the VNTR sequence showed approximately twofold higher luciferase activity than the promoter region harboring the VNTR sequence. G‐quadruplex stabilizers hemin and TMPyP4 reduced the luciferase activity, whereas expression of ATRX led to a recovery in reporter activity. Our results demonstrate that stable G‐quadruplex formation by the VNTR sequence downregulates the expression of α‐globin genes and that ATRX might bind to and resolve the G‐quadruplex.     

Control of cathodic potential for deposition of ZnO by constant-current electrochemical method

For the preparation of functional films and crystals, the electrochemical deposition method has advantages of large-area deposition at low temperature and high efficiency in terms of the raw materials used. However, crystallization through electrochemical processes is not currently well understood. To apply the electrochemical deposition method, it is necessary to better understand the crystallization and the growth mechanism. To investigate the mechanism, it is essential to ensure the reproducibility of the growth process. We focused on cathodic potential as a parameter that affects the reproducibility of the galvanostatic method. The repeatability of cathodic potentials during deposition was drastically improved by optimizing the mask pattern on the electrode and the pre-treatment conditions. As the result, the cathodic potential was able to be controlled by the current density. Furthermore, nucleation and grain growth of ZnO crystals by the galvanostatic electrochemical method are discussed in association with the change of cathodic potential. Changes in grain size at various cathodic currents are also discussed.     

Fluoroalkyl end‐capped oligomer possessing a nonflammable characteristic in silica gel matrices even at 800°C under atmospheric conditions

We succeeded in observing the similar solid‐state NMR spectra (¹H‐magic‐angle spinning NMR spectra) of fluoroalkyl end‐capped N‐(1,1‐dimethyl‐3‐oxobutyl)acrylamide oligomer [R_F‐(DOBAA)_n‐R_F]/silica gel nanocomposite before and even after calcinations at 800°C. This finding suggests that R_F‐(DOBAA)_n‐R_F oligomer in R_F‐(DOBAA)_n‐R_F/silica gel nanocomposite can afford a nonflammable characteristic to exhibit no weight loss behavior even at 800°C under atmospheric conditions. In addition, we had good oleo‐ and hydrophobic characteristics on the modified glass surface treated with R_F‐(DOBAA)_n‐R_F/silica gel nanocomposite even after calcination at 800°C as well as those before calcinations. Especially, R_F‐(DOBAA)_n‐R_F/silica gel nanocomposite‐encapsulated cetylpyridinium chloride (CPC) possessing no weight loss characteristic even at 800°C exhibited a clear UV–vis absorption band around 260 nm related to the presence of CPC before and even after calcinations at 800°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Mechanical Property Evolution during Autoclaving Process of Aerated Concrete Using Slag: II, Fracture Toughness and Microstructure

The mechanical properties were investigated for autociaved aerated concrete (AAC) block samples, prepared using blast furnace slag at 180°C under saturated steam pressures for various times from 1 to 128 h. The mechanical properties of AAC made using slag are comparable to those made without slag. With increased autoclaving time, the compressive strength increases due to the binder effect of the 1.1-nm tobermorite. In contrast, the fracture energy G _F. and resistance to crack growth decrease with increase of autoclaving time. This dependency is caused by the formation of voids around unreacted slag particles.     

Effects of alkylamines and PC on the oxidative stability of soybean oil TAG in milk casein emulsions

The effects of alkylamines and PC on the coppercatalyzed oxidation of soybean oil TAG were studied in milk casein emulsions. Stearylamine showed an antioxidant effect in casein emulsions in the presence of PC, whereas dicetylphosphate acted as a prooxidant. The antioxidant or prooxidant effect could be explained by the electrostatic repulsion or attraction between positively charged stearylamine or negatively charged dicetylphosophate and positively charged copper ion at the interface, respectively. On the other hand, these effects were not observed in the absence of PC, suggesting the importance of PC for charged components to show their activities at the interface. Other types of alkylamines—spermine, spermidine, and putrescine—also inhibited the oxidation of soybean oil TAG emulsified with casein in the presence of PC. The antioxidant effects of these natural polyamines were higher than that of stearylamine. PC molecular species also affected soybean oil TAG oxidation in emulsion. The oxidative stability of soybean oil TAG increased in the emulsion with PC containing oleic acid.     

Improvement of Chromatic Aberration of the Plastic Rod‐Lens Array, 2

Summary: We propose in this paper a new plastic rod‐lens with low chromatic aberration. Since a plastic rod‐lens has a parabolic refractive index distribution, it usually also shows a distribution of Abbe number. This Abbe number distribution is thought to cause the chromatic aberration of the plastic rod‐lens array. We have studied novel materials for a new plastic rod‐lens with low chromatic aberration and have provided new transparent polymer blends consisting of two polymers with different refractive indices and with almost equal Abbe numbers by using a fabrication process based on photopolymerization of methacrylate monomer(s) in the presence of other methacrylic polymers. The process can give new transparent polymer blends which cannot be formed using conventional techniques for polymer blend formation. In this work, tricyclo[5,2,1,0^2,6]deca‐8‐yl methacrylate is used as a high refractive index monomer and tert‐butyl methacrylate is used as a low refractive index one. By using polymer blends including these monomer units, we have created a plastic rod‐lens with lower chromatic aberration.

Molecular structures of comonomers in the study.     

Daily oscillation of gene expression associated with nacreous layer formation

Three major organic matrix components, nacrein, MSI60 and N16 have been reported from the nacreous layer of Japanese pearl oyster, Pinctada fucata. Though several in vitro experiments have been carried out to elucidate the functions of these molecules details have not yet been clarified. In this report, we tempt to clarify the gene expression levels encoding the above three proteins between samples of 1) summer and winter seasons and 2) ocean and aquarium environments by using real-time polymerase chain reaction (PCR). It was confirmed that the biomineralization process of P. fucata is mainly influenced by the circatidal rhythm of the ocean environment. The gene expressions coding for N16 and MSI60 increased at the time of high tide, while that of nacrein increased at the time of low tide. The similar tendency observed in N16 and MSI60 showed the possibility that both components are secreted simultaneously, supporting a hypothesis that N16 forms cross-linkage with MSI60 to form the membrane. The expressions of MSI60, N16 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were remarkable in winter season, while no variation was found in the expression level of the nacrein gene in summer and winter season. The study is the first attempt regarding the seasonal and circadian rhythms observed on gene expressions incorporated into molluscan shell formation. The results will give a new insight into the relationship between molluscan physiology and the mechanism of shell formation.     

Daily oscillation of gene expression associated with nacreous layer formation

Three major organic matrix components, nacrein, MSI60 and N16 have been reported from the nacreous layer of Japanese pearl oyster, Pinctada fucata. Though several in vitro experiments have been carried out to elucidate the functions of these molecules details have not yet been clarified. In this report, we tempt to clarify the gene expression levels encoding the above three proteins between samples of 1) summer and winter seasons and 2) ocean and aquarium environments by using real-time polymerase chain reaction (PCR).It was confirmed that the biomineralization process of P. fucata is mainly influenced by the circatidal rhythm of the ocean environment. The gene expressions coding for N16 and MSI60 increased at the time of high tide, while that of nacrein increased at the time of low tide. The similar tendency observed in N16 and MSI60 showed the possibility that both components are secreted simultaneously, supporting a hypothesis that N16 forms cross-linkage with MSI60 to form the membrane. The expressions of MSI60, N16 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were remarkable in winter season, while no variation was found in the expression level of the nacrein gene in summer and winter season.The study is the first attempt regarding the seasonal and circadian rhythms observed on gene expressions incorporated into molluscan shell formation. The results will give a new insight into the relationship between molluscan physiology and the mechanism of shell formation.     

Electrochemical detection and control of interactions between DNA and electroactive intercalator using a DNA-alginate complex film modified electrode

The surface of a glassy carbon electrode was modified with a DNA-alginate complex film in which water-soluble DNA was encapsulated into a calcium-alginate gel. The resulting modified electrode (DAFE) was used to detect ethidium bromide (EtBr), after its accumulation on the electrode. The intercalative behavior of EtBr for dsDNA in the film was investigated by measuring the electrode response based on the intercalation of EtBr separated from nonspecific interactions (electrostatic interaction). The accumulation of EtBr in the dsDAF was enhanced by applying a negative potential below -200 mV at the dsDAFE. When a positive potential above +700 mV was applied to the dsDAFE for a constant time with stirring in a Tris buffer solution, the amount accumulated decreased. These results indicate that it is possible to electrochemically control the accumulation and release of EtBr when a dsDAFE is used. In addition, the accumulation and detection of EtBr in spiked river water samples and daunomycin, an antitumor agent, is described.